I am going to use a pair of the Edcor transformers for a headphone amp. My headphones are 32 ohm, and I'll probably put a 32 ohm resistor in parallel. Do I need to do anything different to use the amp as a preamp? That is, will seeing a 10K, or a 50K input impedence cause reflection problems? Will I need to use a different resistor on the secondaries, or would transformers with a 600 ohm tap be a better idea? Thoughts?